Improvement in lifting-jacks



J. B. FAYETTE.

Lifting-Jack No. 20|,l73. Patented March 12, 18,78.

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INVENTOR WITNESSES ATTORNEYS.

- N. PETERS. PHDTO-LITHOGRAPNER. WASHINGTON. D. C- I UNITED STATES- PATENT OEEIoE.

JOHN B. FAYETTE, OF OSWEGO, NEW YORK.

IMPROVEMENT IN LlFTlNG-JACKS.

Specification forming part of Letters Patent No. 201,173, dated March 12, 1878; application filed February 8, 1878.

.To all whom it may concern:

Be it known that 1, JOHN B. FAYETTE, of the city and county of Oswego, and State of New York, have invented a new and useful Improvement in Lifting-Jacks, of which the following is a specification:

In the accompanying drawing, forming part hereof, Figure 1 is a side view of my improved lifting-jack, and Fig. 2 is a longitudinal section of the same.

Similar letters of reference indicate corresponding parts.

The invention will first be described in connection with the drawing, and then pointed out in the claim.

A represents the base of the jack, which is made sufficiently large to give the said jack a firm and stable support, and prevent it from being pressed into the ground. To the base A is attached a hollow standard,B,of convenient height, and which has a flange or collar formed upon its upper end for the shoulder of the tubular nut O to rest upon. The tube of the nut C may be made so long as to reach to, or nearly to, the base A, or of an; desired length, and of such a size as to turn freely within the standard B. In the upper part of the nut G are formed holes to receive a lever or hook wrench for turning it. D is the main or lower slide, upon the lower part of which is formed a screw-thread fitting into the screwthread of the nut G. The upper part of the lower slideD is enlarged and made tubular to receive the upper slide E, upon the upper end of which is formed a head, to rest against the axle or other object to be raised. To the opposite sides of the enlarged upper part of the lower slide D are pivoted the lower ends of two connecting-bars, F, the upper ends of which are pivoted to the opposite sides of the lever G at a little distance from its forward end, so as to serve as a fulcrum to the said lever. The forward end of the lever G is forked to receive the upper part of the lower slide D, and to the ends of its branches are pivoted the lower ends of the connecting-bars H. The upper ends of the bars H are pivoted to the opposite sides of the upper slide E just below its head.

With this construction the power will be applied in line with the slides D E, so that there will be no side strain.

In using the jack it is placed beneath the object to be raised, and the lever G is raised, lowering the upper slide E to its lowest point. The nu O is then turned to raise the lower slideD intil the head of the'upper slide E strikes against the object to be raised. The lever G is then operated to force up the upper slide E, raising the said object.

By this construction the object will be raised the full throw of the machine. As the lever Gr approaches the end of its downward movement the adjacent ends of the two pairs of bars pass each other and the central line of the machine, so as to lock the slide E in its raised position, and prevent the possibility of any pressure forcing it downward.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The combination of the base A, the hollow standard B, the tubular shouldered nut G, the screw-slide D, the upper slide E, the two pairs of pivoted connecting-bars F H, and the forked lever G with each other, substantially as herein shown and described.

JOHN BESON FAYETTE.

Witnesses:

T. G. AUsTEN, E. J. FAYETTE. 

